In printers which receive print data from a host computer and perform printing based on the received data, known is a technique of using a buffer memory for each printing color component as a ring buffer (for example, Japanese Patent No. 3296226).
According to this technique, as a ring buffer can be determined in correspondence with the information amount of each printing color component, the limited memory capacity can be effectively utilized.
Nowadays the printing resolution of printers is further increased, whereas an enormous amount of data is transferred from the host computer to the printers. To efficiently perform the transfer, the data amount may be reduced by compressing image data to be print-outputted. However, the information amounts of the respective color components are not in equal proportions. That is, the ring buffers for the respective printing color components cannot effectively function without difficulty.